The following patent publications and commercially available products are believed to represent the current state of the art:
U.S. Pat. Nos. 4,040,413; 4,148,307; 4,195,637; 4,453,545; 4,676,228; 4,862,874; 5,025,778; 6,007,482; 6,309,346; 6,461,294; 6,585,639;
U.S. Patent Application publication Nos. 2004/0102681; 2005/0124856; 2005/0125005; 2005/0137457; 2005/0165273; 2006/0111610; 2006/0161044 and 2007/0244361;
Double Balloon Endoscope product, including EN-450T5 enteroscope, TS-13140 overtube and BS-2 front balloon, which interface with balloon pump control BP-20 and 2200 video system, all commercially available from Fujinon Inc., of 10 High Point Drive, Wayne, N.J., USA; and
Sleeve Expander Tool product, manufactured by HellermannTyton of 7930N. Faulkner Road, Milwaukee, Wis. USA, and commercially distributed in the UK by Canford Audio PLC of Crowther Road, Wash., UK under catalog number 55-601.